Which way is better to go?

[Charlotte Levvy]

Which way (hostingsource.com or just.hosting) is better to go? 

I plan to host a heavy website. 

[DoubleImpactPR ✔️]

Not entirely sure what the niche and other requirements are for your, as you mention, heavy website.
For a dedicated server, I can sure recommend to check the wide offering of servers available at MojoHost

One host with 27 years of experience, experts in hosting complex, multi-server projects, with own infrastructure and three data-centers in the US and EU alike. 

You can also start smaller, customize your setup according to your needs, and scale, as your requirements grow - hit me up on telegram if you'd prefer to connect directly.