As has already been stated, wing lift is based on how much buoyancy you need to compensate for, and a wing also needs to be able to float your rig on the surface (because there are some places where you take the gear off in the water before reboarding the boat). You can do a pretty good quick and dirty calculation of lift requirements: Given the 5 mil wetsuit, you'll be using a steel plate which is 5 lbs negative. Add a full Al80 (2 pounds) plus your regulator (maybe 2 lbs) and you're about 9 lbs negative. Now, if you carry eight pounds or so of lead for that 5 mil suit (which is what my husband uses) the rig is 13 pounds negative, so any wing lift beyond that will float the rig.
At the end of the dive, you have the 5 lb plate, 2 lbs of reg, 8 lbs of weights, and a tank that's +4, and you should be neutral, so that means you've got no more than 15 pounds of lift from the suit you can lose. Again, anything more than that is enough lift.
As a practical experience story, I have dived my LCD 30 wing (which is far more lift than I really NEED in warm water) for five years with no issues. It is small enough not to have a significant "taco" effect on an Al80. The 17 lb wing I have is more fun -- more streamlined and easier to vent -- but it's also on the borderline for lift with a 5 mil suit, and I wouldn't recommend it for a beginner.
I don't know where Web Monkey dives, but in five years, I've not had to do a rescue of any sort (worse than grabbing a new diver and preventing them from corking) so I don't plan my lift to hold up another diver.
As far as regs go, if budget is an issue, you really don't need to buy SP's top of the line regulator. We bought Aqualung Titans when we got certified, and both of us still use them for single tank diving. They were middle of the road in price, and have proved both very reliable and good to breathe down to 130. I would recommend you buy a brand you can get serviced locally. You might ask why, since you won't be diving locally and you will have tons of time to send things in for service . . . but right after service is the time when things are most likely to go wrong, and it is an EXTREMELY good idea to get your equipment into a pool to check its function before taking off on an expensive dive vacation. And if you find anything not working properly, it's awfully handy to be able to run in panic to the dive shop and say, "It isn't WORKING!"
Take the money you save by not buying the MK25/S600s (which, by the way, are my cave diving regs, and I love them) and buy a dive computer. You will very quickly find that diving tables doesn't work very well. Most dives at resorts are guided, and the guides follow multi-level profiles to maximize dive time, and those profiles will be completely off the charts if you try to plug them into the eRDP.