A full size discone works fine up to 500MHz and I believe that there are some that have a vertical element that receives 27MHz.
That will probably be a $50-$100 antenna and if your bank account doesn't hold that kind of money then you can try a 27MHz dipole you make from electrical wire. It will probably work fine also for the air band if you manage to have it outdoors.
104 inches to each side are fine for 27MHz. Use it vertically and coil up the coax 4-5 turns at the antenna and put some ferrite cores on it to isolate the antenna from the coax shield. That will probably be a total of $20 and you can use RG6 CATV coax.
You can google a better example that includes coiling the coax and using ferrites.
/Ubbe