I got great results from a full shielding job on my Baja. It's still a single coil-guitar with all that pertains, but you can improve the situation considerably.
Any good 3-way will work - CRL, Oak Grigsby. The Fender or DiMarzio branded ones are CRLs.
You can also use a 4 pole 5-way superswitch and do away with the S1. Then you can have your normal Tele settings on 1, 3 & 5 and have your series and phased setting on 2 & 4. I find a 5-way is a lot more intuitive to use.
But...
You can also rewire the stock switch to reverse the series and neck-only settings. ? See below.