Extending my reach (1 Viewer)

Whilst I fully appreciate that nothing can beat getting closer to one's subject, this is not always possible and so I am wondering about the most effective ways to increase my reach.

The main application would be photographing waders here in the Gulf of Thailand (those Spoon-billed Sandpipers are not always co-operative for the camera!)

Currently my gear consists of:
1) Nikon 300mm f4 AF-S and 1.4 TC which I shoot on a D7100 and V1
2) Swaro 65mm ATM HD scope and 25-50x ep. I have attempted a bit of digi-scoping with this on the V1 using a third party adapter attached to the 10-30mm kit lens - but I struggled with it and the lens just broke and is a write off...

So I'm looking for options, which so far seem to consist of:
a) getting a Nikon 2x TC (the latest version, III) and kirk collar - which would maintain AF whilst giving the equivalent of 1,170mm on the D7100 and 1,620mm on the V1
b) getting a Swaro TLS APO digiscoping adapter and balance rail, which would give me more reach (equiv 1,462mm on the D7100 or 2,205 mm on the V1 at 25x) than "option a" but would lose AF.

These options would both cost close to GBP 500 and would be much more preferable to investing an a big prime with the associated cost/weight issues.

Any thoughts on which route would be best to follow, or alternatives, would be much appreciated.

Thanks,

Dave

I'm overwhelmed by the number of replies :bounce:

I guess this means that neither of these options is really worthy of further consideration (or hard cash!).

Having looked around online I haven't found any really good examples of images taken with either proposed set up.

Perhaps the best alternative will be to buy a Tamron 150-600.

Best,

Dave