The desktop computer in my coach (see signature for particulars) does not have a wifi board installed in it. I have obtained a Netgear AC1200 High Gain WiFi USB Adapter that I plan on installing in on...
Personally I would dump the desk top for a nice laptop. Besides space saving it will have wifi card already installed. You really do not need a mifi as any smart phone can be turned into a wifi hotspot very easily. The sleek is nice, but there are other amplifiers out there that will do the same job for less money. JMHO