The Dish and DirecTV LNBs are equally unsatisfying because they cover the higher band of frequencies where those companies broadcast their encrypted programming.
If you are interested in real FTA, that band of frequencies, is slightly lower.
Also, Dish and DirecTV use circular LNBs - the FTA service uses LNBs that can select vertical and horizontal signals.
If you are actually interested in real FTA service, there are three sites with lists of all the birds, frequencies, and programming.
FTAlist and
GlobalCM are much easier to use than the
Lyngsat site, but the latter is still very helpful for many technical details.
A good size for a dish would be 30" to 36".
Any larger is usually much higher price to ship (by a lot!)
Of course, if you pick up a 36, 39, 48" dish locally (surplus) and outfit it with a suitable LNB, that's certainly okay, too.
Iceberg has spent a lot of time preparing beginner info, which you'll find posted at the top of the FTA section.
It contains a wealth of
getting started info.
A number of us have experience with Twinhan StarBox USB receivers.
The StarBox I is supported (so far as I recall) by two commercial programs, plus whatever comes with it.
Those would include MyTheatre, which though challenging to set up, may be one of the best.
The StarBox II, a slightly more recent model, has drivers that might let it run with DVBdream software.
If so, I would certainly recommend giving it a look.
The I and II are distinguished by -A at the end of the model number.
Something like 7021 for the I, vs 7021A for the II.
We have a DVB section here on the forum with more detailed info, and all the popular receiver software packages have support forums, too.