Hey TD, if you think your flying skills will get better or that you'll get to use them more often flying a heavy instead of an RJ I'm here to tell you that you're wrong. I flew RJs for years and now I fly the 747-400 and I now do more flying on automation and less takeoffs and landings by far. At my current airline if you fly manually above 1000' the other guy in the cockpit will become visibly uncomfortable and their handling skills leave much to be desired. The airplane does not fly any differrent than any other, and most of your time and effort will be spent on managing automation... far more than the RJ. Watching the autopilot for 12 hours in cruise and speaking to one after another controller over HF radio or spending over an hour each time you go thru customs in Bombay India or having the pleasure of experiencing the interesting smells in places like Hong Kong is not called experience or skill, it's called "pain in the @ss".
Even if you have lots of heavy international time, unless you also have at least 1000 hr. jet PIC to go along with it you're not considered competetive for most jobs. So getting the jet PIC is certainly the priority if your aim is to be more marketable.
Cheers