Modern half-bath copper DWV configuration
As I understand it, you are mainly just irked by not having combo-wye fittings.  Well, a combo-wye (short for combination wye and 8th bend) is nothing more than a normal wye with a street 45 bend (male AKA spigot on one side, female AKA hub on the other).  What you would do is solder the 45 into the hub of the wye, and, there you have it: a combo-wye.

The toilet vent can be downstream of the drain.  In fact, the IPC will say that it can be as much as 12 feet away if your pipe slope is 1/8" per foot.  That may be your easiest option:  Tie the toilet vent and toilet drain in separately.