You *can* use a Tial wastegate with the F-MAX manifold. You just need to specify when you order your manifold which wastegate you will be using. F-MAX makes wastegates compatible with the following wastegates:
1. standard HKS
2. Turbonetics Deltagate
The Tial is the "best" and has awesome construction and uses very good materials, including inconel, which is very heat resistant.
The HKS is also a very nice piece as well and support plenty of hp.
I would stay away from the Deltagate due to poor quality and a high number of diaphragm failures reported after their use.
Go with the Tial or the HKS.
1996 200SX SE-R
GTi-R powered with F-MAX kit
98 se-r w/ p/r cai,jwt s3 cams, stillen header, courtesy exhaust, ur pullies, JUN flywheel, ACT clutch, eibach springs, kyb struts, st sways, cusco camber plates, f/r strut braces,stillen lower control arm brace,SMC BAKB, motul 600 brake fluid, lotsa bushings, and a bunch of other crap