tim, it sounds like if you want to advance towards warbirds of any size then you are going to need more room and more plane to fly, do you know there is a flying field right down the road in Half moon bay where you can fly elec. as well as glow planes and helecopters.
the "peninsula channel comanders" www.flypcc.org , we have a cam on the field and weather on the web, as well as a call in # for wind conditions at the field with a up to the min. recording .
it sounds like you have been doing the go it alone method, and are headed in the right direction,but do you know if you belong to a club you can get instruction as well as help with your plane for free from very skilled pilots who are always willing give you hands on help,are you a AMA member?
you should be, just for the insurance policy it provides you, in case of the unforseable mishap,like hitting someone and causing injury no matter where you fly and you get a magazine also as part of the membership fee.
most clubs in and around the bay area require AMA membership.
if you are interested in flying warbirds then you might want to think about a glow powered plane somthing like the mustang PTS if you are already using the sim and flying electrics then you have the general basics, and with some instruction you would be able to fly the mustang trainer, there about 400$ complete with radio and engine.it really depends on how far you and of course your son want to take it and how fast.
you can spend a small fortune on park flyers only to have to retool when you get to a larger model.
when I restarted a few years ago I got a NEXTAR trainer and it was a awsome training platform for getting back into glow powered RC, but it sounds like you have advanced a bit past that, something to consider before sinking more $$ into park flyers is where you want to head in the hobby.
BTW I take my boys down to the field and there into it its a wide open space next to the ocean check it out joining a RC club isn't to bad of a deal.