I can absolutely relate to this dilemma, as it's similar to some soul-searching that I did in 2008.  My thoughts:

First off, that's terrific that you have a couple different directions that you can pursue.  Too often, I fear that many folks don't see much of a career path in front of them, and I think it's great that you see multiple.

Second, without drawing too many conclusions, you're probably working for a pretty solid company.  In contrast, there are many employers out there that will tell you to keep your head down and do the job they hired you for, and that training you in an adjacent skill-set is out of the question.  So, regardless of how this plays out, I challenge you to appreciate that your employer allows/encourages this type of opportunity.

Finally, to the crux of the matter, what are you passionate about?  What makes you tick?  Corporate Recruiters contribute in a very important way, as do HRIS Specialists, as do HR Generalists, but these are very different roles.  At the end of the day, how would you prefer to spend 50%-60% of your waking hours contributing to the company?  You could make money doing any of the three, but I believe the X factor here is in what you enjoy doing and how you find meaning in your work.

Now, I'm well aware that I essentially answered your questions with more questions, so I'll share my own experience, for context.  In 2008, I had 1 1/2 years of staffing behind me, and I was a year into my next role as a corporate recruiter.  I felt a little like I'd fallen into a rut, from a professional development standpoint, and I wasn't sure if recruiting was the long-term role for me, possibly in favor of a career move to HR Generalist.  I didn't know who to talk to about this, so I decided to pursue my PHR, for two reasons: 1) I'll learn more about employment law, benefits, employee relations, compliance, compensation, etc., and 2) if I do decide to make the leap, I'll have the PHR certification to hopefully lend credibility (this was before the SHRM certifications existed).  

What I learned was well worth the time, energy, and money I invested - I have a tremendous amount of respect for the folks that perform all the previously-mentioned HR duties, BUT, at that point in my life, I was meant to be in talent acquisition, all day, every day.  

In conclusion, I'm not suggesting that you stay in recruiting - far from it.  Nor am I suggesting that you'll find the answer in studying for a certification - it might not be there for you.  Rather, I'm encouraging you to find a way (e.g. job shadowing, a reflective walk in the woods, etc.) to uncover which role you're going to be most passionate about for the foreseeable future.

I totally agree with Dan in his well written response, some soul searching will give you the answer. Do what you love and you won't regret it. The only thing I will add is: do you love spending more time with people (interviewing, screening, etc)? Or do you love analysis, data, reports, individual work? In the case of HRIS management, you will definitely find yourself working more with the data rather than the constant people interaction. So you need to know your personality and what works for you. I truly prefer a mix of both because I find that it works for my personality.

Good luck!  

Nice to have a choice.  I think the business partner role is favored as it can provide greater exposure to HR dsciplines, which help you learn about future paths in your career.  Also, I hear a lot of HR people complain about "being outside" and a partner role should expose you to the joy of being inside.

I think that transitioning from recruiter to HRBP is a pretty logical next step. Good recruiters already know A LOT about the company through the hiring process and have built relationships with hiring managers and employees who you will work with. If you enjoy the people side, HRBP is usually a meaty, roll your sleeves up and impact the business role. However, if you are done with people and their unpredictability/drama and enjoy analyzing and providing recommendations based upon data and systems, HRIS might be the best next role for you. Both have pros and cons, have tremendous career potential and are options are fantastic for your next step! Good luck!