Hi Alex,
I have a 4.5" Tasco T11 for sale here on IIS.
http://www.iceinspace.com.au/forum/s...ad.php?t=58071
A few things that might put you off:
It is 114 x 900
It has a 0.965" focuser
I reckon the 900mm FL makes it the perfect size for a kid sized Dob.
The 11T is known for its very good optics. Various people have put 1.25 focusers in these, or you could get some decent 0.965" eyepieces.
Cheers,
Jason.