fortune 100 corp strategy group or boutique merchant bank for PE?

I'm currently debating two offers, one from a corporate strategy group within a F100 company and from a boutique consultancy/merchant bank firm (I'm an experienced hire, post-college 2-3 years). I know it's a longshot from either place, but I'm hoping to transition into a PE firm after 2-3 years. Or perhaps go to MBA, and figure out a post-MBA PE option.

The corporate strategy has high visibility within the overall organization, and consultants within the group are expected to transition into other areas of the company after 2 years. From what I can gather, those that wish to head to MBA end up at top 10 schools. The work/life balance seems much better here, 45 hrs/wk.

The position at the boutique firm would give me a chance to not only work in a strategic consultancy but also get into alternative investment in the future (firm is building a fund for primary direct investment). The firm focuses on small to mid-market. Standard working hours are 60 hrs/wk.

The salaries are very similar. I'm thinking at the second place, especially with primary direct investment experience, I would get a shot at PE firms a few years down the road, though I'm not too sure how PE firms view associates with 4-5 post-college experience. I've heard some feedback that the F100 corporate strategy group would have better PE options, but i'm not so sure since I don't think i would get any deal exposure here.

Given the second offer is a bit more unique, would this look more favorably to MBA schools?

Any other thoughts here would be very helpful - thanks!