Adapting yarn for a pattern

[knitcindy]

I bought some Patons Decor yarn from someone on Craigslist last month. The cardigan I'd like to make, however, calls for Patons Shetland Chunky.

Can I use the pattern I have if I just make the next size? And would I go up or down a size?

I would love to find a v-neck cardigan pattern in a beginner/ easy pattern that I could use this Decor yarn with. It has been VERY difficult to find a pattern for just a simple, long sleeve cardigan that you don't have to sew the button bands on at the end. I wish someone would publish a book of SIMPLE patterns (simple in difficulty AND simple in design).

THANKS for your help!!
knitcindy