It think it comes down more to what you are comfortable working with.
I have a table saw, bandsaw, compound mitresaw and scrollsaw - the bandsaw got the majority of the work.
In the portables - circular saw, jig saw, reciprocating saw - the jig saw was invaluable and could have done all the bandsaw work (for anyone with a strict tool budget) - the circular saw and a scarfing jig attachment was how I made my plywood scarfs - so in my case, this was a "must have".
A couple assorted hand saws may also make some aspects of the job easier - I used a flush cut saw (about 6" long, teeth on both sides) and a pull saw (about 24", fine teeth on one side, coarse on the other - Stanley makes both models and they are relatively inexpensive) extensively when fitting the chine and sheer - prefer these to normal handsaws because they allow a little more precise control - but a keyhole saw or coping saw probably would have worked fine in tight spots.
All my sanders are portable (if you don't count the drums on my drill press) - 21" belt, 5" disk, 1/3 sheet and 1/4 sheet - use all of them but if I could only have two it would be the belt sander and 1/4 sheet (or maybe the disk) - nope, "I" need them all
Absolute must have is a portable planer - I have a 6 amp 3 1/4" model that saved hours (if not days) in the rough fairing. Additionally, if you use silicon-bronze fasteners, these planers will go right through them when fairing - it's a little tough on the blade, but it's not dangerous like hitting stainless steel. The portable planer can also be used for plywood scarfing in place of the circular saw/jig.
Also as noted, if you can get rough lumber at a significant discount, a planer (12-13") and possibly a jointer (even a benchtop 4" model) might well be worth the initial outlay (I'm building an (almost) 26 footer, so the difference in cost between rough and finished lumber when you are talking hundreds of board feet more than offset the cost of the tools).
A couple of good chisels, a wood rasp (or 4 or 5 - always putting them down and can't remember where
) and lots of clamps - F clamps, C clamps, clothespin style etc are also in order (if you think you have enough clamps, get double what you have and then you will only be a few "short").
Also a couple of drills - one corded and one cordless (or a couple of cordless with spare batteries) are very handy. Many screw holes should be piloted and it saves time if you aren't constantly swapping bits. I pilot and bore with the electric and have a dedicated cordless screw gun for all the screws (unless you are going for the West System method with zero fasteners in your build)...
Yes, Plywood is "real" wood
A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it