If you are only operating over a narrow frequency range, using a crystal oscillator in place
of a VFO may be adequate. (Some digital modes are much more critical for frequency
stability than others.)
The BITX design may be a good starting point.
I'm not that familiar with the kit offerings currently available, but here are a few
designs to consider. Just about any SSB transmitter strip using a CB output transistor
is probably going to work, then question then becomes the VFO/XTAL oscillator.http://www.intio.or.jp/jf10zl/14mssb10w.htmhttp://www.qrp.pops.net/willy.asphttp://www.vanyi.net/homemade/homebrew-hf-ssb-transceivers/