Advice on Dell Keyboards w/6 Key Rollover

My hobby is brailling. I need a keyboard that has 6 key rollover (ability to press keys fdsjkl simutaneously). At work, I've been using the Dell Quiet Touch for a very long time. Fortunately, new keyboards were purchased and the Dell business multimedia has six key rollover. So, I now have a new keyboard at work and a lot of hope that there are additional keyboards with
6 key rollover. Advice on additional keyboards with six key rollover would be appreciated. The keyboard that came with the computer that I recently brought for my home does not have six key rollover, so I need to replace it with one that does. I'll replace it with the one that I have at work unless someone knows of a more comfortable one on the market.

I also would like advice on microphones. I have the Andrea VoiceCenter. I thought that it was a microphone for online classes. I was wrong. I need to buy a microphone to use it. Obviously, I'm really excited to find out if I can record and translate to Braille. I mostly scan documents for translation to braille at work. I checked the Andrea Web site and they have one that they recommend that is around $34. I also saw one available from Dell for around $15 that had excellent customer reviews. The microphone from Andrea looks like it is a table top model. The one that I'm referring to that is available from Dell fits on the head.

I have a Dell Dimension E510 with Windows Service Pack 2.

Advice is appreciated.

Thank you.