Before you do anything, consider this. Before I bought my own "Profoto" ringlight, I used to rent one and had our local (Los Angeles) strobe repair guru make me an adapter to use it with my Norman packs so I wouldn't have to rent a Profoto pack every time. I don't know what kind of pack you're using, but you might consider having him make you an adapter too, its a lot easier. If you really want to change the flash itself, consider sending it to him (or any other qualified tech) and let a pro do it, because its tricky, the Profoto and Acute II are wired differently, have different voltages, and use different flashtubes. (But the reflector is the same).
Here's what I did: I bought a hardly-used Acute II from a friend. If I had simply had my tech make up an adapter for that it would have burned out the flashtube prematurely because the Acute II tube fires at 500 volts and my Norman packs put out 900 volts. To fix this, he re-wired the ringflash like a regular Profoto (which would be 1000 volts), and exchanged (for a slight charge) the barely used 500v flashtube I had, for a slightly used 1000v flashtube he had, and changed the connector to the one on a Profoto. So now I have a 1000v Profoto flash, that says "Acute II" under the gaffers tape I put on it (the tape says "Profoto" so if I loan it out, people know). So now it will work with any Profoto, and with my adapter, my 900v Normans. Additially, he made another adapter to use it with my Norman 400B (450v battery unit) with works fine with no negative effect on the ringflash.
I don't recall how much the modifications cost, but I think it was around $100, maybe $200 with the adapters and flashtube swap. I think he'd do one adapter cable for around $50. If you'd like something like this done for you, use my name and contact:
Flash & Video Repair
937 N. Cole Ave. #1
Hollywood, CA 90038
Andy Pearlman Studio