I agree with Tokis about only the one bristlenose, unless possibly two females. Two males will fight, and a male/female pair- well, you'll have baby bristlies coming out of your ears. Also, there won't be enough space for her to escape his attentions.
Also agree about the guppies, though I personally would keep a same-sex group, saves a lot of hassle. Either a big male group- you could fit in 6-8 easily, or a smaller group of 3-4 females (less showy but nicer IMO). I would use the spare inches from the bristlenose to enlarge the school of neons to 8-10.