I have a home in Illinois, a home in las Vegas, now I want to purchase another home in las Vegas that will be my primary residence in a couple of years when I retire, can I still be eligible for a 15 year loan from my 401k??

The rules of your specific plan will determine what your options are for taking a loan. But be aware that any loan outstanding when you leave the employment of your company (retire, quit, are fired, etc.) MUST be repaid in full within 60 days or will be recharacterized as withdrawals. Which means income tax and erly withdrawal penalty (if applicable) would be due on the outstanding amount. So my advice is: don't take a loan if you think there is high likelihood of not paying it back fully while still on the payroll.