theres not very much.
the ones i see are just a M\S tire.
LT27+8.50+R14 is one of very few sizes that LT, M\S tires are made for 14" rims
there are some 14" tires that have a rating of P, but there a H\D P tire, you can save 5.00 to 35.00 bucks a tire or so.
but there not ment for all rock roads, just a long rock drive way.
or some on road, bad weather.
75-series 14" Radial Tires Size, Tread width, Cross Sect Width, Overall diameter, Rev/mile, Rim Width
...................185-75R14 ............4.8................. 7.2................ 24.9..........809....4.5-6
...................195-75R14 ............5.1 .................7.7 ................25.5 .........790....5-6.5
...................205-75R14 ............5.3 .................8.0 ................26.1..........773....5-7
...................215-75R14 ............5.6......................................26.7.......... 755....5.5-7.5
...................225-75R14 ............5.9......................................27.3 ..........739
...................235-75R14 ............6.1......................................27.9 ..........723
the rest of the sizes for bigger rims are at this link.
http://www.carnut.com/specs/tires.html