If you are only looking at a Noc Mig setup, I personally would would be careful of investing in a parabolic mic.
I know that many people use parabolas for NocMig work, but I have never got to the bottom of how much 'work' the parabola is doing. If you house cardiodal mic facing in to the dish, then the mic should in theory only pick up reflected and amplified sound from the dish. The problem here is that the focus is only about 15 degrees. This mean that if a bird flies directly over the mic at an altitude of 100m and travelling at 30mph, it would cross the focus in 1.96 seconds, so you need to be pretty lucky to get a call. If however the bird was on a parallel track north, south, east or west or the pole of the focus, the bird may miss the focus altogether. You can of course point the parabola at the horizon in the likely direction of travel - in this case you will pick up approaching birds (so may have better odds), but won't pick-up high flying migrants. This also means you need to have an unobstructed view in the direction you want to point the dish.
To confuse things, people use omni mics in parabola, which would pick up sounds from all directions, so would pick up un-amplified sound direct from a bird out of focus. The issue then is what percentage of recorded sounds are reflected and amplified sounds, and what percentages are recorded directly without amplification. I have asked the guys at the Sound Approach about this issue as I think they use a Telinga Parabola, but didn't get a response - if they are using the twin science module, they have both a omni and a cardiodal mic, so can pick thinks up amplified, but also direct, although this should be obvious as the two mics record to separate channels.
I tried to resolve this question by setting up a recorder with two identical mics, one in a dish and one without, but I need to pick a better migration spot to get some stats - what I can say for sure from my experiment, was that the parabola wasn't picking up anything too high to be picked up for a direct recording. The dearth of recordings means that I need to rerun the experiment in a better spot
I now use a passive recorder (see Wildlife Acoustics), These are weatherproof, and good sensitivity and can run for many days. I use one without a parabola and get pretty good results, but you could house one in a parabola as belt and braces - the following link shows a setup using a SM Mini
Nocmig with an SM4-mini. - You will see my comments on the page regarding whether the system is mainly catching direct sound of amplified reflected sound.
The other thing with a SM Mini, if that that can be quite good fun to pack on a holiday and are small enough to take anywhere.
Cheers
Jon
