Any Omni-directional mic will work in the parabolic - but the mic is where to spend your money. I usually open my office/seawatch hide window and point the parabolic upwards and out a bit over the beach. This has the advantage that the recorder is inside and can be powered.
You need some software too - I recommend Audacity and Raven [from Cornell] I use Audacity to listen and make quick assessments on sonagrams, isolate calls I want to look at further and cut out noise, whilst Raven is better for producing final sonagrams
In other news there was a Yellow-browed Warbler in ther back garden yesterday afternoon
Up to 61 species now this year with the surprise capture of a Tree Sparrow Yesterday. Never common on North Wirral, these species is declining markedly, so I was less that 50:50 about recording one this year, let alone ringing one.
Also new were Wigeon, Jackdaw and Rock Pipit.
A Fulmar Feb 23rd was unexpected.
In January I rang 85 birds of 15 species, but only 10 of 6 species in February.