I agree that you have everything you need for instrument and most of what you need for commercial.

However...I would pony up up for a second VOR receiver for cross-fixes. I could do it with one receiver, but I have a lot of GA instrument time. I would hate to have to learn with only one receiver.

I would seriously learn instruments on steam gauges and save the hi-tech stuff for later. You will have PLENTY of time in your career to learn GPS (it's easy), but instrument training is probably your only opportunity to develop a good second-nature ability to navigate with raw data.

If you want a GPS for backup and can afford one, great. Even a non-IFR GPS would be just fine for SA. You can learn the GPS while doing commercial time building, but I would not install an IFR GPS until after your instrument checkride...if you have one, you will have to use it on the checkride.

You can do most of your commercial in a 152, but will have to transition to a retractable/complex airplane for the last ten hours and the checkride. Do the entire checkride in the retractable.