Hello hy-tek. No apologies please - we are all learning! I can't help you specifically with the XH7988, but personally I would keep an eye out for an 802.11g device (54mbps compared to the 11mbps of the .11b). 11g equipment is not much more expensive now than 11b, and gives you a bit more headroom in bandwidth.
You may wish to consider whether the equipment you purchase has connectors for the antenna(s), or the antennas are permanently mounted. This has implications for adding external antennas - some people are happy modding devices to add antenna sockets, others don't want to touch the insides (hence the need for factory sockets).
Keep an eye on
Pricespy for an idea on what prices are good.
Sometime the "brand names" are a better choice as the manufacturers tend to make updates available to address functional and compatibility issues.