Alex, 328VR2 is an excellent start. Many folks have also given you very good advise. You will find your setup ideal for taking swiftlets/sparrows/swallows on the fly. With some handholding experience, you will find it useful in low light, thick foliage conditions without the hindrance of a tripod. For more controlled conditions, a good 3-series 4section Gitzo will come in handy. Beyond that, you will need to find the sweet spots (optimal aperture/shuttle mix) in the various TCs that you will use.
Most importantly, do not hesitate and approach the more experienced shooters in the field. Most of them are willing to share a note or two but you will need to make the approach first..
The one lesson that I have learnt in this space, get the best that you can afford. Good luck!