Tire size help .. and thoughts on used tires ?

[nefarious986]

Hey guys .. I bought rims about 6 months ago and now I cant find the email with the tire size thats supposed to go with these rims.

They are the `ebay` ruger rs5 that should be 8.5 x 19 (fronts) and 10.5 x 19 (rears) .. although when I measure with a measuring tape, the 10.5 is more like 11.5 from left to right and the diameter is more like 21" .. lol.

I m wondering whats the best size to put on these. I did some research and it seems 235/35/19 works for the front .. and 275/30/19 works for the back ?

The car isn't lowered yet, although it might be dropped a bit soon. Will be running with 7mm spacers for the rear.

And I was shopping for tires on Ebay (looking for new ones since I have a paypal discount code) and some of these used tires have really affordable price tags. A bit wary of buying used tires even though seller has almost perfect feedback from 30K+ feedbacks. What are your thoughts ?