your iclear 30's wont work on mech mods mate, well when i say wont work they will fire but you'll get unbelievably bad performance from them as they are dual coil usually at 2ohm which when i use have to be pumped up to around 4.5 volts where as your mech will only run 3.7 without a kick of course, for a mech with a decent RBA you want to be looking at around 1.5 ohm and less for decent performance, i coil my rba's at between 0.8 - 1 ohm and this gives me great performance.
i would recommend you do some heavy research before even placing a battery in your mech mod as they can be very dangerous if you dont know what your doing, if you build a coil and it shorts your battery will expel too much power making it very hot and maybe even blowing up, every battery has a different limit on how much power or "amp's" it can consistently output safely, so you need to be aware of what batteries you pick. i recommend effest IMR.
as for atty's for mech, you have drippers such as the igo's, then you have genesis atomizers which require a mesh wick (i dont use these too faffy and sort of old technology imo, plus you need a blow torch), then theres your bottom coil rebuildable's such as kayfun, taifun, aqua etc. all these are re-buildable. you can in theory use any tank thats rebuildable in a mech but i find that achieving the desired low ohm's have negative effects on smaller tanks that arent built for mech's, for example i rebuilt a protank 2 to 1ohm a few month ago in order to use on my mech and it simply couldnt handle the heat, the rubber insulater burnt and the whole tank simply became too hot.
also yes 100% you need an ohm checker, NEVER EVER put anything on a mech without testing.
i know it must sound scary and im not meaning to make you panic but you do have to understand how it works otherwise it can be very dangerous. BUT do your research, get the right kit and you will be flying, i was new to mechs only 3 months ago and i also had a lot of homework to do but now i've learnt it all and know exactly what i'm doing i will never look back, i mostly exclusively use mech's now, 4 months ago i never thought i would say that
oh and welcome to the wonderful world of true vaping bliss that is mechanical mods