Yes the whiteblock M90 bolts right up, you can even use an R clutch and flywheel which would make a nice stockish setup.
Tremec T5s are hardly rated to what a stock internal T5 can put out with a reasonable tune (North of 400 FW or in this case - RW NM)
Your best bets will be an M90 - although very costly and near impossible to replace if you lunch it,
T56 although costly and still a rather agricultural gearbox
Getrag from the commos or early BMW 3 series offerings - 260s are common enough but are all getting quite old although are a nice enough shifting box - Will require considerable modification to the bellhousing.
Toyota R154 or R155 variants - R154s are getting rare and are very exxy for boxes as is without rebuilding, R155s however are worth near shit-all but have ratios that arent all that nice. Super stout box, will take near as much as you can throw at it.
https://www.driftmotion.com/T-1UZ-R154-TA-p/dm2141.htm
Nissan CD009 - Modern 6 speed shifter, comes out of the 350zs and a few others of that flavour, fantastic shifting box, super stout and will take an absolute beating. Known to take 1000nm like its nothing. Has a non removable bellhousing BUT there are kits out there that make it work out quite nicely if you dont mind getting a little creative with a grinder. Also fantastic ratios.
Deeworks makes a super snazzy adaptor that makes this possible
https://www.deeworks.ca/product/volvo-whiteblock-and-toyota-2jz-to-350z-370z-g35-g37-6-speed-transmission-adapter/
Id avoid going with the older tremec T5, with anything more than a moderately worked B230FT and your gonna have a bad time