Finding the correct wheels in very good condition will be plenty spendy. I would venture to guess in the $100 each range or more. The important part is that they are still round and don't wobble. Buying used wheels long distance and therefore, sight unseen, is risky. You may want to look at restorable wheels and have them restored too.
Coker has replacement fiberglass tires but if you've never driven a car with belted tires, be in for a shock. They handle like sheet compared to radials. They do have look-a-like radials too which are better but they are all expensive.
The reason you have a front rub now is the 245 is too wide on the front. 235 is about the limit and I like 215x65 for a front tire. It brings the tread width down to around 6-6.5 inches and the 65 series sidewall gets the height back up some to look right. In your case, you will be looking for a 70 series. I think 205 or the 215 is the equivalent of the G78.
1967 GTO; Gulf Turquoise on Black, 4 speed, buckets SOLD
1967 Camaro ss/rs 350
1966 Chevelle SS 396
1966 Chevelle Malibu
1970 Chevelle SS 396
1962 Impala SS
1952 Chev 2 ton flat bed
1938 Chev coupe