  We present 16-GHz Sunyaev-Zel'dovich observations using the Arcminute
Microkelvin Imager (AMI) and subsequent Bayesian analysis of six galaxy
clusters at redshift ($z \approx 1$) chosen from an X-ray and Infrared selected
sample from Culverhouse et al. (2010). In the subsequent analysis we use two
cluster models, an isothermal \beta-model and a Dark Matter GNFW (DM-GNFW)
model in order to derive a formal detection probability and the cluster
parameters. We detect two clusters (CLJ1415+3612 & XMJ0830+5241) and measure
their total masses out to a radius of 200 $\times$ the critical density at the
respective cluster's redshift. For CLJ1415+3612 and XMJ0830+5241, we find
M_{\mathrm{T},200} for each model, which agree with each other for each
cluster. We also present maps before and after source subtraction of the entire
sample and provide 1D and 2D posterior marginalised probability distributions
for each fitted cluster profile parameter of the detected clusters. Using
simulations which take into account the measured source environment from the
AMI Large Array (LA), source confusion noise, CMB primordials, instrument
noise, we estimate from low-radius X-ray data from Culverhouse et al. (2010),
the detectability of each cluster in the sample and compare it with the result
from the Small Array (SA) data. Furthermore, we discuss the validity of the
assumptions of isothermality and constant gas mass fraction. We comment on the
bias that these small-radius estimates introduce to large-radius SZ
predictions. In addition, we follow-up the two detections with deep,
single-pointed LA observations. We find a 3 sigma tentative decrement toward
CLJ1415+3612 at high-resolution and a 5 sigma high-resolution decrement towards
XMJ0830+5241.
