I use a penguin bio-wheel 200 but am looking to get another one as I'm going to be breeding and overstocking slightly. So I would suggest a penguin bio-wheel 200 and if you wish to spend the money penguin bio-wheel 100 also. Advantage to that is if one filter breaks you have one running and your tank won't recycle.
Because that only filters 150 gph, perferably you want 10x gph for your tank size so you would really want 300gph but is not necessary. You can use the 150 but it won't filter as much thus you can't keep as many fish and you need to do larger water changes than if you had a larger filter. A good rule is overfilter, understock. Get where I'm going ?
They are ok but I like the bio-wheels because you can change all the filter media and not have to worry about getting rid of the beneficial bacteria because it's on the bio-wheel. People also like the aqua-clear because you can put in lots of media and have things like the bio-wheel. The whispers only have two stage filteration carbon and filter floss thus when you change the media you have to leave some in because beneficial bacteria grows on the media and removes unseen bad stuff in your water keeping your ammonia, nitrate, nitrite levels down, if you remove all of this then you are recycling your tank. So I would not suggest a whisper, either aquaclear or bio-wheel since you can choose what filter media you wish to remove and what to keep.
No problem, instead of buying the filter inserts for them buy a big bag of filter fiber/floss whatever your lfs sells and take a handfull and stuff it in where you would normaly put a filter insert. Just stuff enough in to make the bio-wheel spin, saves a lot of money and as the wheel ages it won't spin with the normal inserts.
I'd pass on the Penguin biowheel since the Emperors are superior and use biowheels too. For your tank get a Emperor 280 or 400. The biowheels on the Emperors aren't affected by any reduced water flow from the cartridges being clogged or dirty since they have their own spray bars that control the rotation speed of the wheel. They also have a nice 1 touch flow reducer for feeding time.
Get an Aqua Clear that pumps 300 gallons per hour (gph should be on the filter's box). That's what I have over my 30 gallon tank and it is PERFECT. Never had a problem with it and it provides EXCELLENT filtration. It's THE BEST hang-on-back power filter in my opinion.
I have a Penguin Bio-wheel 150 in my 29 gallon tank with Maxi-jet powerhead and i have never had any problems. I have plenty of flow of water i can see my plants moving in my tank. Best filter and powerhead i have ever owned. But i dont plain to over stock my tank. But if i do i will be getting another pump for my tank.
I honestly don't think one is better than the other as far as the Aqua Clears and Bio Wheel style filters go.. The only minor difference between the two is owner preference. They both work very well and do what they are supposed to do.