I just found your thread here after seeing your post in support. It looks like you have received a lot of good suggestions, much of it from very experienced divers - much of which I support in agreement, the rest I am not as qualified as they to discuss.
You seem intent on owning your own kit now, tho - ok, fine. You even have a couple of good escape plans if you decide you don't like your first collection. I never dived any Mares products so I can't help you there, but buying what your trusted buddies like and know well does have some merit. They can help you with it much more than if you chose other products.
I am going to comment on some of your other items...
- force fin "slim fins" - have you tried them in a pool? I tried them diving and like them - (octosuckerr)
- scubapro crystal VY single window mask - get one that fits well. (used it snorkeling like it)
- scubapro mk25 - that's what I upgraded to (thanks this is the important stuff I dont know at all)
- steel 130 tank - you're a big fellow, so a big tank would be beneficial. (thats what I figured - harder to get in the boat - but hey - everyone else does it)
- tusa spg - I couldn't care less who makes my spg (I worry about this as - lol - I am really worried about gauges malfunctioning...maybe thats stupid)
- zeagle tech bcd - don't know (my buddies swear by this and I am like them in a lot of ways - so if they're wrong - it would be one of the first - ready to take a risk)
- suunto gekko - not at all my favorite. This subject deserves much more study - see Computer sub-forum. (gotcha - lack of backlight bothers me - my "brothers" are split on this - one says mares m2? with constant backlight - other 2 say gekko for menus and a divelamp charge in water - they carry a lot of lamps (x3) the lakes I guess..)
- suunto sk7 compass - it's a compass.
(this is the only one I am sure about - I am very good at land orienteering - its a no brainer for me) I have 3 Suunto land compasses for land navigation - superb.
If you're going to dive in your local lakes of 55 F, I'd suggest a minimum of a 7 mil suit, heavy gloves, neoprene socks, heavy booties that will fit over the socks, and a heavy hood. For better opinions on this, talk to the divers on the California and Pacific Northwest sub-forums, as they dive such all the time.