Well, I did a little more research and found a good website that has many diferent wave files of different BOVs and some opinions on each. Here is the site:
From what I have read, the Apex has been known to leak. I dont like the sounds of that. And the sound of it is kinda boring. The HKS one seems to get rave reviews. Evidently it can not leak due to its design. Thats good. The sound is quite a high chirp. Not bad. I just might go with the HKS unit because of their reputation and quality. I will have to give a phone call to see if I can get a lower price.