Read your way through this...
http://www.bbastrodesigns.com/tm.html
Recently I bought a 102 f5 thanks Zane
and put an ES 30mm 82º eyepiece on it and
A revelation compared to any other eyepiece I tried in my first 4" f5. A tiny bit of FC and a TFOV of 5º... very nice. Perhaps a Nagler 31mm might be better, but my wallet says no way!
Matt