Bigger is better ,I have 4 Spydercos and the smallest one is the chinook3 so I might not be the best judge. If you are going to get a combo you should get the endura. Essentially you are getting 2 knives and the combo does not give you much room to work with either one.
I prefer a Plain edge although I do like some spydies in fully serrated like the masood and my Stainless police. Spyderco has excellent edge geometry on their knives so a properly sharpened PE edge is going to be sharper than 98% of the knives you are used to.
You will be amazed at how handy a nice sharp plain edge is especially as you always have it handy. Why look for scissors because you can even cut paper better and straighter especially with a long edge like the Endura.
You have to decide what handle now as well.
Stainless is nice cheap ,looks good ,gets scratched but is easily fixed.The nain drawback is it is slippery. It is also very discrete.around 70$
FRN ,cheapest at 50$ not slippery at all ,cool colours and tough. Some people find it feels cheapy plasticy but it is a very well put together knife.
G10 Like smooth expensive FRM but feels not cheapy.
Carbonfibre ,a carbonfibre Spyderco(I don't think they make Delicias in CF?)is expensive for a spyderco but cheap for knives that have that kind of quality and materials.