Congrats Mike.
Glad you got it.
You'll have to weigh up which will be it's primary use.
I'd say keeping the 20D for terrestrial will serve you very well.
If you will be doing more astro than terrestrial then get it modded and use it for astro.
Either way you've got the best of both because the 350D is still an excellent model for astro, and you already have got it setup as such with the necessary cables etc.
The only thing I'd suggest is doing some tests and deciding which will serve you better for which application.
Anyway it's great buy and a good addition to the kit.
