You can't use 2 modems.

Buy an appropriate length Cat5E cable and one of these:

TP-LINK TL-WA901ND Wireless N300 3T3R Access Point, 2.4Ghz 300Mbps, 802.11b/g/n, AP/Client/Bridge/Repeater, 3x 5dBi, Passive POE https://www.amazon.com/dp/B002YETVXC/ref=cm_sw_r_awd_NffuwbS6WP3NN