Which map?

[gchntr]

Hello everyone,
First time user. I just purchased the Garmin Oregon 600. What free map here would be comparable to the $129 Garmin South Central 24K? Texas is my main concern at this point so would it be the Texas Topo by maps4gps? Is Texas Topo 24K or 100K relief? I haven't received my 600 yet, it's due on Tuesday. Very excited about it although after reading some feeds on here about downloading and installing maps it sounds a little intimidating. I hope I can figure it out. Thanks in advance for any responses.