Different flavours. LNS is damn neutral and is a improved low-bias Lambda. 207 is a bit brighter sounding than the 202 (typical 2/3/4/507 brightness) but has similar traits to that of the 202. 202 is really balanced sounding and fairly neutral. So no recessed treble/mids, not very bright sounding, not very bassy it is pretty close to middle. Lambda Pro is a bit laid back sounding with good detail retrieval and probably the most dynamic sounding stat in the lambda family, the bass is very close to that of a dynamic transducer. The Lambda Pro + SRM-1 MK2 is a wonderful sounding bliss combo, more so than the T1S pairing I've tried. The Lambda Pro was originally marketed with the SRM-1 MK2 or the SRD-7SB MK II energizer. I haven't heard the LP-Sig but some prefer it to the LNS, some say it is more detailed, some say it is more coloured sounding compared to the neutralness of the LNS and it is not very bassy either.
If you have the budget for a good amp and the 007 Mk1's, then just go for that. Or you can collect Stax like me.