Hi, skinz, welcome. My only advice I can offer is if you can do all your own parts purchasing, mechanical work, adjustments, wheel truing, fitting, then just pick which ever one looks best to you. If not, do not buy.
If looking for a bike to "get back into cycling to lose some weight", while I applaud your efforts, you really need a bike that is fully serviced and road ready and even if used should come from a bike shop