18x8's come in 4.5 BS, which fits well. The 18x9.5 come in 5" BS which seems to be a good choice.
Here they are cheaper then Summit with free shipping to you.
$999 free shipping
http://www.ebay.com/itm/CPP-Boss-338...item1e787c16b0
I bought the Ridler 18x8 in grey from them for $560 free shipping, super fast shipping from them.