Which AWS instance type for peak calling with ChIP-seq data?

We have generated ChIP-seq and RNA-seq datasets and are considering using Amazon’s AWS cloud computing service to run various peak calling programs, assess peak reproducibility between replicates, and genome browser visualization. AWS offers several instance types and I have no clue as to which may be more appropriate for our intended applications. I will be using a home MacBook Pro with 8 GB RAM, but other team members will be using PCs. Is there an instance type which is obviously preferable? What have other AWS users found to be suitable?