i forgot to specify that i'll be using strut, the bending will be virtually inexistant
You still have bending!! You ALWAYS have bending - the strut is just a different way to approach the overall wing design which distribute the loads (ALL spar carried loads!) to 2 pick-up points instead of 1....
Everything said about spar activity and suggested approach to a tailored spar stay valid! Just the spar will have a different tappering layout and different sizing compared to a cantilever...
Alibaba carbonfibre: you CERTAINLY want a material certification and a complete data-sheet!
Carbonfibre comes in as many forms as glassfibre and varies in quality just as much!
Just ordering from Alibaba because it's a good price is a near certain way to disaster!
Carbonfibre is AWESOME, but a serious ***** to actually get ANY benefit!!
You need to EXACTLY calculate your requirements (including safety factors, which are usualy higher for carbonfibre for it's severe failure mode - no warning by yielding - it just snaps, so you need to have a lot more safety factor to compensate), then EXACTLY calculate with the fibre at hand (which you cannot if you do not have the full data-sheet), then you need to design the exact layout of the fibre and the expoy you want to use (again complete data-sheet needed!).
The ONLY data-point you do not need at this stage is "price".....
The weight savings possible with carbonfibre come - usually - with a VERY high price, because of the exact design neccessary to realise the possible weight savings....
Frankly - I BET you would be able to build lighter and cheaper with NONE-carbonfibre!
(Are you equipped with vacuum? ...and a oven big enough for your spar?)
If you buy a ready made rectangular tube - you are already sub optimal as it is not optimized....
Ask Space-X about carbonfibre ....and why they switched to stainless!!!
You mentioned struts - maybe your ride is similar to a Zenith? Check the various build videos and have look at the wings and especially the spars!!