Hi, Shifty. I have a soft spot for this since I'm from Oklahoma (I went to that
other university...), and I have a bit of experience with EV's.
Have you taken the test to get the state license yet? It's easy, the main hurdle is the insurance they require you to carry.
For stiffer springs, call coil springs specialties out of St. Mary's, KS. (
Springs for Custom Cars and Custom Situations - COIL SPRING SPECIALTIES). Just give them the info. on your basic vehicle, and tell them how much weight you added at the front and back. They will custom make you springs. A front
and back set for my fiero (
Dave Brandt's 1986 Pontiac Fiero) was like $320 if I recall.
If you have issues with the dolphin controller, contact Chris Zach (you can reach him from the elec-trak forum (
Elec-Trak.com) and he has been known to hang out on the EVDL (
The Electric Vehicle Discussion List) as well. He has repaired many of these on USE prizms and S-10's, and can program/reprogram the controller as well as help with any faults. He has also started a "known issues" list and has repaired controllers that many would have just tossed in the scrap heap.
As far as concern over a lot of batteries, it isn't a big deal. I use a string of 19, and would have used more if they would have fit. I'm right at GVWR, and the car handles fantastic with the new springs. Your batteries are smaller, so should not have a big impact, although the USE prizm used Hawker 26 Ah batteries, about half the size and weight of the YT's. AND they get 30-40 miles range with the smaller batteries. Crunch some numbers and see what size you really want to use. Of course then you may get to be limited on what is available.
A high voltage string increases efficiency, and you can use smaller cables. The important thing is to keep them balanced. By the way, I've heard bad things about Optima quality since Johnson Controls took over. You may want to do individual cycling and capacity tests on them before installation to weed out any bad eggs. They (Optima) have also refused warranty claims on batteries used in EV's for some people on the EVDL. Exide makes the orbital blue top and the purple 34-XCD, and those are comparable in size and capcity to the optima YT's, so you could look at those as an option. I believe there are also some hawker clones out there in various sizes, and the power-sonics like what I used, come in a lot of sizes (plus they have handles!).
In any case, good luck with this conversion. It should be really slick.