Yes, those are exactly the springs. However, the red springs are fairly soft (2.6 lb/in rate)
The 2" long springs are technically for buggy front but you can get away with using them on the front of an AMP, you'll just have to run the pre-load collar wayyyy down. For longer truck shocks (like on the AMP) the 2.5" front and 2.75" rear are a better fit and give you more room to adjust pre-load.
You'll note that the stiffer range of springs are designed for the front and softer for the rear. Feel free to experiment. On my AMP/Circuit I run red in the front and orange in the back.
Check Ebay and Horizonhobby.com. Although sellers on Ebay seem to want to ask two or three times the original price because the springs are "vintage." (Ugh.) I've had good luck just visiting local hobby shops- I've found several that have had plenty of old stock... and they didn't charge extra for "vintage-ness."
Here's a list of (old) Losi spring part numbers:
FRONT BUGGY SPRINGS
Losi Part #
LOSA5128 2" Spring 2.5 Rate (Red)
LOSA5129 2" Spring 2.9 Rate (Orange)
LOSA5130 2" Spring 3.2 Rate (Silver)
LOSA5132 2" Spring 3.5 Rate (Green)
LOSA5134 2" Spring 3.8 Rate (Blue)
LOSA5135 2" Spring 4.1 Rate (Black)
REAR BUGGY & TRUCK (front and rear) SPRINGS
Losi Part #
LOSA5144 2.75" Spring 1.4 Rate (Gold)
LOSA5146 2.75" Spring 1.6 Rate (Gray)
LOSA5147 2.75" Spring 1.8 Rate (White)
LOSA5148 2.75" Spring 2.0 Rate (Yellow)
LOSA5150 2.5" Spring 2.3 Rate (Pink)
LOSA5152 2.5" Spring 2.6 Rate (Red)
LOSA5154 2.5" Spring 2.9 Rate (Orange)
LOSA5156 2.5" Spring 3.4 Rate (Silver)
LOSA5158 2.5" Spring 3.7 Rate (Green)
LOSA5160 2.5" Spring 4.1 Rate (Blue)