What longboard to buy??

Hallo everybody---- I want to now what longboard I buy because I have been surfing in shortboard for 4 years now but I think I would like to take up longboards also. I am 5'8" 70kg from Portugal and maybe I try performance longboard?? I try my friends mini mal 7'2" and it was very fun and turned easily i could do some wrapping cutbacks and top turns. I wants to keep this performance type surfing in longboards but ride a size around 8'0". Please advice me onto the right size of longboards thank you
. As well I apologize for my bad English I have only been living in California for 1 and one half of years.
