Your diamond card is very ok for a VL card. 2MB, Trio64 with 135MHz RAMDAC installed gives you decent speed and compatibility in both DOS and Windows. And when connected to a TFT a 135MHz RAMDAC is sufficiant for most scenarios.
Otherwise I would recommend fast S3 cards like: S3 928, S3 Vision 86x cards, Vision 96x cards and S3 Trio cards. All are good for DOS and Windows. Of course there will always be cards from Tseng Labs, well known for their throughput under DOS. Go for the W32i or W32p cards with a good 135MHz truecolor RAMDAC. While the Tseng cards excell in DOS the S3 cards are better for Windows.
There are other cards that are OK, too, but not soo good for DOS like Cirrus Logic (compatible but slower than Tseng and S3) and ATi Mach32 and Mach64 cards (great for Windows, but slower than Tseng and S3 under DOS.).
I would avoid Trident cards or the very entry level Cirrus cards like the 5424. But the 5428 cards do their job OK. If you come across a Diamond Viper VLB - avoid it. It has the Weitek 9xxx Chipset, speedy under Windows but it has a seperate Chip for DOS compatibility (from OAK Tech.) which is very very slow. Such a card is only interesting for crazy collectors like me and a handful of others from Vogons 😁
When you ask for controllers you may look for cards with a BIOS installed for LBA support. These cards support at least 2GB HDDs, some even 4 or 8GB HDDs. These controllers of course work well with CF cards installed instead of real hard disks.
Promise:
http://www.amoretro.de/2012/09/promise-eide23 … i-io-karte.html
Side:
http://www.amoretro.de/2012/09/side-jr-plus-j … i-io-karte.html
Cache controllers are also a very nice thing. You don't need smartdrive or any equivalent buffering program if you have a cache controller. These are many variants, Tekram and Promise were most popular these days.
I have a Tekram myself, I like it alot. But it lacks a CD Interface, so you need to add another controller for that or have to use the sound cards CD-interface if available. The Tekram also supports mirroring via adress shifting (Like Raid 1 if you want). It has an onboard 20MHz 286CPU, it is a system in a system 😀
Tekram:
http://www.amoretro.de/2012/01/tekram-dc-680c … -local-bus.html
My favourite VLB board is the Shuttle HOT-419 R3. I love it! Maybe the SiS 471 might be a bit faster, the OPTi 895 based Shuttle board is more stable for sure. Works with Cyrix and AMD 5x86 CPUs and YES it does the 50MHz busspeed with 2 VLB cards installed (depends on the cards of cause)
Shuttle HOT-419 R3:
http://www.amoretro.de/2012/08/shuttle-hot-41 … otherboard.html
Well if you want to go PCI, I wouldn't recommend the HOT-433 if you don't want to build a "fastest 486 ever" system. The HOT-433 has its quirks and doesn't have a usable PS/2 header. I would recommend the Zida 4DPS or the BIOSTAR 8433-UUD. They both are also very fast and have working PS/2 headers.
Cheers,
Fabian
www.AmoRetro.de Visit my huge hardware gallery with many historic items from 16MHz 286 to 1000MHz Slot A. Includes more than 80 soundcards and a growing Wavetable Recording section with more than 300 recordings.