Tire size help

[jrcui]

So, I found a set of 18"s (fronts are 7.5 x 18 et 50 and the rears are 10 x 18 et 65). I knew I need spaces for the rears so I bought some 20mm spacers that came with the extend bolts. I just got the wheels back from the painter and now I need to find the appropriate tires.

The PO had them on a Vanagon so the front tires have a lot of outer wear and the rears are mis-matched (Toyo and Michelin). The fronts were 225 40 18's and the rears were 265 35 18's.

Are the current tire sizes right for a 2000 Base or should I be using a different size? Trying to figure out the proper sizes so I can hunt for the best deals.

Thanks in advance!