So first off, I bought a strap on system? It's a leather harness awith a little widget to which you affix a strap on dildo.

I shopped around and found the Doc Johnson Vac-U-Lock system. This is very nifty. Basically there is a little widget on the strap-on. It is a fixing point. You add some powder to the dildo you want which is compatible with the system and it vacuum seals the dildo onto the fixing point.

Most dildos are now compatible with the system.

I shop for dildos.

Get a selection. Look for "the most realistic feeling" dildo. Heck I am no expert so the internet leads me.

I get a smallish one to test her out with, 6,5 inches, one more or less my size (I get the length right but dick is very thick and finding one that matches the thickness and length is impossible so we do a thinnish 8,5 incher) and a giant 11 inch one which is thicker than me. 

I have a plan now.