Yes, you can get a pvc threaded male and hope it has the same thread type to screw into the pump outlet. Then glue a straight piece of PVC to that. Then glue a PVC wye to that. Then glue straight pieces to the wye. Then glue threaded females to that. Then screw hose barbs to that....
See what I'm getting at? All too complicated, bulky and hideous.
Buy a hose barb wye as I previously stated. If you can't find one, just stay with the tee. Sure the tee may cause a little bit of resistance, but I really don't think it's enough to be concerned with. You'd be surprised how powerful these pumps are.
When I built my bog, I was concerned with using regular pvc elbows. I wanted to use wide sweeping ones. Believe me, it really doesn't make much, if any difference.
When I open my clean outs, the rush of water is extremely powerful.
Now, unless there's another reason for replacing the tee.... Perhaps it doesn't physically fit in a particular location?