Overall solid combo.
I'll 2nd what CP said about connectors. You can make you own with 1x2 tubing and a couple pieces of .125 thick plate and be substanially under the retail cost of new ones. They may not be as trick as contoured, weld to the floor units, but they will achieve almost the same amount of rigidity. I'd also recommend you move these to the top of your list ahead of any other changes. Firming up the unibody yeilds dividends above handling and will also help reduce squeaks, rattles, and other small annoyances that a 40 year old car has developed.
For the suspension combo, I'd say 1.0 t bars if your set on using a 1.25 sway bar, or 1.03 t-bars if using a 1.125 sway bar. If cost is a factor, 1.25 sway bars tend to be a bit more expensive than the more readily available 1.125 units. I've seen 1.125 units as cheap as $100 for solid bar units. I also woudn't get too hung up on avoiding Addco, PST, Hellwig or any of the other solid bar manufacturers. They all make decent products, only the end attachments are a bit cheesy on some. However, you can replace the simple L bracket with some weld on, factory style brackets. You can find these on Summit's website.
The .75 rear bar won't be bad. Match it to some Espo heavy duty or mopar XHD springs. If you have the stock 4.5 leaf pack and you want to keep costs down, you may want to add an extra full length leaf to get the rate up around 140-150# without changing out the whole pack.
For order, I'd say;
rebuild the suspension
subframe connectors
front sway bar (assuming you don't have one now, otherwise swap position with the shocks)
shocks
t-bars
rear sway bar
