Alright l am 6' 160 lbs and ride on average waist high beach break waves.l have been using a 6'8 twin retro fish for a year and feel really comftorable on it.l wanna move to the next level so l can surf more vertically.What kind of shortboard should l get? l was thinking a ci flyer but theyre really expensive.

Thanks!
also what height should l go for?

Get a Al Merrick Flyer 2, or the Al Merrick MBM.The MBM is a beast and you will love it!

Get the Al Merrick MBM in a 6'2. l have it and love it! good luck

The Lost SDII l & Lost shark r both designed for smaller surf, so they might be cool in ur waist high beach break. l just bought an SDII, because l am old a fat, & so far it seems fine for me. Channel Island Al Merrick Flyer I l or M4 r also cool for small surf.
l do not know where u surf, but l am sure there r some good quality local shapers who could build u a stick from the blank out. l have owned two custom boards in 42 years, & they have been two of my favorites. Go to ur local surf shop, & see what the scoop is on local shapers. You can get a board that fits u size, skill & break, usually for no more than yo will pay for an off the shelf name brand.
If it is Spring time where u are, go for it, u can usually get a board in about 6 weeks. If l knew where u lived, l could make a couple recommendations, but u will do fine at a surf shop. Good luck.

how about instead of getting an al merrick get a board shaped by your local shaper?

That way you are supporting your community, getting a board more attuned to your style and it will probably still be cheaper then a big name right now.
The board wo not say Al Merrick on it but it will be more special and you will feel more comfortable on it knowing it was shaped just for you.