.biz domain is good to rank in google serp..... I heared that .biz sites are not that much effect in google serp
any top level domain is good for serps. It only matters when type in is considered and click ratio is checked. i think people like more of a .com or .org most often as compared to a .biz strictly as far as serps are concerned .biz play same as a .com would do.
I won't effect your SERP but maybe it will effect your click ratio since people who don't recognise the TLD maybe refuse to click because of that.