Could you please recommend a wireless lavalier microphone and receiver system that can be used with a computer sound card. I have read the article "Interfacing Professional Microphones" and at the end it refers to you as a source for recommendations. I have to take cost in to consideration and am aiming for a less expensive mic.
The budget-priced Shure PGX series will likely work.
HOWEVER, note that many computers generate local Radio Frequency Interference (RFI) that can impede the proper operation of a wireless mic. Unfortunately, this can only be determined with the use of expensive test equipment OR by getting a wireless system and trying it with your computer. So make certain to purchase the wireless from a Shure dealer that is willing to take it back if it does not work with your computer set up.