Thats my thing, BKs and ATBs are great skimmers. But they are VERY expensive for what they are IMO. You pay a ton more cash for that Extra little bit of performance.
A 250 would probably be better. If you NEED it or not is hard to say. I have a 300 gallon (280 plus external overflows) Right now I just use a H&S A200-1260. Its doing the job. If I were to replace it tomorrow I'd probably get the Reeflo 250 just cause the 200 is only rated for up to 400 gallons. My tank is 300 gallons plus a 100 gallon sump. Sure my running water volume with LR coral, ect ect is much less but still I would like a little more buffer. Your better off oversizing a little then under.