I think the Rage Theater VIVO chip is the creme of the crop and superior to any of the TV cards including the ATI cards, but the Radeon VIVO cards are limited to composite video-in, instead of offering the superior S-Video input of the AIW cards. My opinion is dump the TV card and get an AIW if you want the best quality captures and most stable package, IF a thrd party was making a VIVO card, it would likely not be competively priced with the ATI card anyway. I'm also not so sure a Radeon VIVO card would play nice with another capture card anyway. Seems I remember that using a TV wonder in conjunction with a Radeon VIVO meant disabling the VIVO of the Radeon and having to use the TV Wonder as the VIVO card as well, which seems to defeat the purpose of having the VIVO to begin with. I simply hooked a VCR to my VIVO anyway and used its tuner from the VCR, no TV card needed.
Looks to me you could either:
Pick up a Radeon 8500 128, and pair it with your present TV card
OR
Pick up a AIW 8500 128
OR
Find a Radeon 8500 128 VIVO(Good luck with this one), and use a VCR as the tuner.