What water pump for a 318?

[Tonefiend]

I know most woudl gank the 318 for somthing bigger, but It's staying for now. 

I need a new water pump.  My car was converted to non AC yet is still has the stock water pump.   I know the AC and non AC cars use a different W.P.  What are the differences and which one should I get?? 

Also I assume I can just go to Napa or Kragen and get one. 

[Aussie Challenger]

  Stock water pump will work, check prices, the Napa stores that I have dealt with when in America have been more helpful than some of the chain parts stores.   

[Chryco Psycho]

the difference is 6 or 8 blade impellor , both fit & work but the 8 blade draws more power

[Tonefiend]

Thanks!